FDA peptide categories explained: Category 1, Category 2 and the 503A bulks list

Quick answer FDA keeps several different lists, and the one that counts for compounding is a federal rule called the 503A bulks list; Category 1, 2 and 3 are only FDA's interim way of sorting ingredients that have been nominated for it. In April 2026 FDA took twelve substances off Category 2, and in July an advisory committee recommended six peptides for the bulks list, according to news reports, against the advice of FDA's own staff. Today none of those six is on the bulks list or in Category 1, so licensed pharmacies can't compound them. Use this page to test any claim that one of them is "legal now", and watch for a proposed rule from FDA, which hadn't appeared as of October 2026.

The three tests an ingredient has to pass

Under section 503A of the Federal Food, Drug, and Cosmetic Act, a licensed pharmacist or physician may compound for an individual patient from a bulk ingredient only if it passes these tests, in order:

1. If a USP or NF monograph (an official quality standard) exists for it, the ingredient has to meet that monograph and the USP chapter on pharmacy compounding.
2. If there is no monograph, the ingredient has to be a component of an FDA-approved drug.
3. If there is neither, the ingredient has to be on FDA's list of bulk drug substances for 503A compounding, known as the bulks list.

The ingredient also needs a valid certificate of analysis and has to come from an FDA-registered establishment. Most peptides people search for pass neither of the first two tests, so for them the bulks list is the only lasting route. How a 503A pharmacy works is explained here.

Bulks list or category: what each one means

The bulks list is a federal regulation, 21 CFR 216.23. FDA adds to it only through notice-and-comment rulemaking: a proposed rule, a public comment period, then a final rule. The first final rule, published on February 19, 2019, listed six substances. Because the list is a rule, a press release, a committee vote or a removal from another list doesn't change it.

While FDA evaluates nominations for the list, it sorts nominated substances into interim categories under its January 2025 interim-policy guidance. Substances nominated on or after January 7, 2025 are no longer placed in any category.

Category 1 is enforcement discretion. It is not FDA approval, not a place on the bulks list and not a legal authorisation, and FDA can move a substance out of it. FDA's category list was last updated May 14, 2026.

What "removed from Category 2" means, and what it doesn't

In April 2026 FDA removed twelve substances from Category 2, effective April 22, after the nominations for them were withdrawn. On FDA's list they are BPC-157, cathelicidin LL-37, dihexa acetate, emideltide (DSIP), epitalon, GHK-Cu (injectable routes), KPV, PEG-MGF, Melanotan II, MOTs-C, Semax and thymosin beta-4 fragment (also known as TB-500).

FDA's guidance says a withdrawn nomination, and the category update that follows, "do not reflect a determination by FDA" about the nomination. So removal does not mean:

• the substance is on the bulks list. Only a final rule does that.
• it is in Category 1. FDA did not move these peptides there.
• licensed pharmacies can compound it. With no monograph, no approved drug, no bulks-list entry and no Category 1 placement, compounding it sits outside what FDA has said it will not act against.
• FDA decided it is safe. FDA's own staff proposed in July 2026 that none of the seven substances reviewed that month be added to the list.

On July 23 and 24, 2026, FDA's Pharmacy Compounding Advisory Committee met on seven of the twelve. News reports say it voted to recommend adding six to the bulks list and voted against a seventh, DSIP. The votes are non-binding, and FDA had posted no results as of October 6, 2026. What the vote means is explained here.

That leaves six peptides in a gap. Pending FDA rulemaking, licensed pharmacies can't compound them, because they are not on the bulks list and not in Category 1. As of October 6, 2026, FDA's category list was unchanged since May 14, and a search of the Federal Register found no proposed rule to add them.

Why GHK-Cu is the exception

FDA's May 14, 2026 list puts GHK-Cu for non-injectable routes, such as a topical cream, in Category 1. It had been removed on April 22 when its nominations were withdrawn, then added back after a nominator clarified on May 5 that it was withdrawing only the injectable route. Injectable GHK-Cu is in no category. FDA says it intends to consult its advisory committee about GHK-Cu before the end of February 2027, along with four other substances.

Compounded medications are not FDA-approved, and a place on one of FDA's lists doesn't change that.

Is this right for me?

This page is for you if someone has offered you one of the six peptides, or you've read that one is now allowed, and you want to know where it stands. It can't tell you whether a treatment suits your health; only a licensed provider who knows your history can, and the answer may be no.

What you can do now:

• Ask the seller which of the three tests, or Category 1, its ingredient meets. FDA's lists don't show the six on any of them.
• Ask which state board of pharmacy licenses the pharmacy, and look it up through FDA's BeSafeRx state links.
• Treat a "research use only" label as a warning, not a medicine. What that label means is explained here.
• Take the goal that brought you here to your own doctor.

If FDA's rules change, a licensed provider in your state would still review your health history and decide whether anything fits you.

How it works

1. Enter your email below. The form at the end of this page asks for your email address and state, and nothing about your health.
2. Hear from us only if it becomes available through a licensed provider. We write about availability and nothing else, and you can unsubscribe anytime.
3. A licensed provider still decides. Being on the list is not a reservation or a prescription. If FDA's rules change, a provider licensed in your state reviews your health history first and can decline.

FAQ

Does Category 1 mean FDA approval? No. Category 1 means FDA says it does not intend to take action against compounding with the substance while it finishes its evaluation, if conditions are met. It is not approval, and FDA can change it.

Is a Category 2 substance illegal? It's a policy category, not a ban written into law. FDA says it would consider taking action against compounding with Category 2 substances under its general enforcement policies.

Did any of the six peptides move to Category 1 in 2026? No. As of October 6, 2026, none of the six was in Category 1, 2 or 3 on FDA's May 14, 2026 list. Non-injectable GHK-Cu is in Category 1, which is a different substance.

How does a substance get onto the bulks list? Through a proposed rule, public comments and a final rule. The first round took about 26 months, and FDA has published no timetable for the six.

What this means for you

As of October 2026, licensed pharmacies can't legally compound these six peptides for patients: none is on FDA's 503A bulks list, and only FDA rulemaking changes that. If FDA lists them one day, the legal route would be a prescription from a licensed provider in your state, filled by a licensed pharmacy; compounded medications are not FDA-approved. Until then, products sold online as "research use only" aren't made for people.

The July 2026 FDA peptide vote, explained covers all seven peptides the committee reviewed and what has to happen next.

Safety information

None of the six peptides is an FDA-approved drug. Compounded medications are not FDA-approved either; the difference is that a licensed pharmacy makes them for one patient, on a prescription.

What FDA has said about the six, on its safety page (current as of April 22, 2026):

• Immune reactions and impurities. For several of them, FDA says compounded drugs may pose a risk of immunogenicity (an immune reaction to the peptide) and may have peptide-related impurities.
• Little or no safety information. For BPC-157, Semax and Epitalon, FDA says it has identified no or limited safety information and lacks the information to know whether the drug would cause harm when given to people. For TB-500, MOTS-c and KPV, it says it has not identified any human exposure data.
• Not a verdict either way. These statements are not a finding that any of them is harmful, and not a finding that any of them is safe.

Products sold online as "research use only" are a different, unregulated market that carries additional dangers: no licensed pharmacy makes them for a patient, so no pharmacy quality standards apply.

If you have used a product like this and feel unwell, stop and tell a doctor exactly what you took. Seek care at once for trouble breathing, swelling of the face or throat, or a spreading rash. If this is a medical emergency, call 911.

Sources

• 21 U.S.C. 353a, Pharmacy compounding. law.cornell.edu, accessed 2026-10-06
• 21 CFR 216.23, Bulk drug substances that can be used to compound drug products in accordance with section 503A. ecfr.gov, accessed 2026-10-06
• FDA. List of Bulk Drug Substances That Can Be Used To Compound Drug Products in Accordance With Section 503A of the Federal Food, Drug, and Cosmetic Act (final rule). Federal Register. 2019;84:4696. FR Doc. 2019-02367. February 19, 2019. federalregister.gov, accessed 2026-10-06
• FDA. Interim Policy on Compounding Using Bulk Drug Substances Under Section 503A of the Federal Food, Drug, and Cosmetic Act; Guidance for Industry; Availability. Federal Register. 2025;90:1136. FR Doc. 2024-31546. January 7, 2025. federalregister.gov, accessed 2026-10-06
• FDA. Interim Policy on Compounding Using Bulk Drug Substances Under Section 503A of the Federal Food, Drug, and Cosmetic Act (guidance for industry). January 2025. fda.gov, accessed 2026-10-06
• FDA. Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act. Content current as of May 14, 2026. fda.gov, accessed 2026-10-06
• FDA. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (interim categories list). Updated May 14, 2026. fda.gov, accessed 2026-10-06
• FDA. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (interim categories list). Version updated April 22, 2026, archived copy. web.archive.org, accessed 2026-10-06
• FDA. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Content current as of April 22, 2026. fda.gov, accessed 2026-10-06
• FDA. Pharmacy Compounding Advisory Committee; Notice of Meeting; Establishment of a Public Docket; Request for Comments—Bulk Drug Substances Nominated for Inclusion on the Section 503A Bulk Drug Substances List. Federal Register. 2026;91:20465. FR Doc. 2026-07361, Docket FDA-2025-N-6895. April 16, 2026. federalregister.gov, accessed 2026-10-06
• FDA. July 23–24, 2026: Meeting of the Pharmacy Compounding Advisory Committee. Content current as of August 6, 2026. fda.gov, accessed 2026-10-06
• FDA. Briefing Document, Pharmacy Compounding Advisory Committee, July 23–24, 2026: Introduction. fda.gov, accessed 2026-10-06
• FDA. Meeting of the Pharmacy Compounding Advisory Committee (early announcement of a meeting before the end of February 2027). Content current as of April 15, 2026. fda.gov, accessed 2026-10-06
• ABC News. FDA advisers narrowly vote to add 6 peptides to drug compounding list (news report of the vote; FDA had not posted vote results). abcnews.com, accessed 2026-10-06
• FDA. BeSafeRx: Locate a State-Licensed Online Pharmacy. fda.gov, accessed 2026-10-06